Internally cooled electrode for hyperthermal treatment and method of use

An improved electrode assembly for use in hyperthermal treatment of tumors in humans and animals wherein the tumor and surrounding tissue is heated with radio frequency energy by applying a pair of uninsulated conductive electrodes on opposite sides of a portion of the body containing the tumor such that an electrically conductive connection is made between the electrodes and the body portion to which they are applied, a radio frequency electric alternating current being passed between the electrodes at a magnitude selected to cause heating of the tumor beyond a predetermined temperature level while minimizing heating of tissue surrounding the tumor, said improved electrode assembly comprising an uninsulated conductive plate adapted for electrically conductive engagement with a surface portion of the body including the tumor for passing an electric current through both the tumor and surrounding tissue, means for interconnecting said conductive plate with circuit means for producing said radio frequency energy, means forming passages in heat exchange communication with said conductive plate, means for circulating a fluid coolant through said passages in order to limit temperature rise within surface portions of the body beneath said conductive plate, means forming a chamber including outlet jets arranged adjacent the periphery of the conductive plate and directed outwardly of the periphery so as to be toward the surrounding surface portions of the body, and means connected with the chamber for supplying cooling fluid under pressure thereinto, whereby heating in surface portions of the body immediately surrounding the conductive plate is minimized during the hyperthermal treatment.